Modern electronics are ubiquitous in healthcare. For example, monitoring devices often include electronic components and algorithms to sense, measure, and monitor living beings. Monitoring equipment can measure vital signs such as respiration rate, oxygen level in the blood, heart rate, and so on. Not only are monitoring devices used in the clinical setting, monitoring devices are also used often in sports equipment and consumer electronics.
One important measurement performed by many of the monitoring equipment is heart rate, typically measured in beats per minute (BPM). Athletes may use heart rate monitors to get immediate feedback on a workout, while health care professionals may use heart rate monitors to monitor the health of a patient. Many solutions for measuring heart rate are available on the market today. For instance, electronic heart rate monitors can be found in the form of chest straps and watches. Chest straps are often quite accurate, but they may be quite bulky and wearing them is not always comfortable or desirable. More compact electronic heart rate monitors such as e.g. watches are often not very accurate due to a high amount of noise present in the signals provided by the sensors of these monitors. The noise is often caused by the fact that the user is moving and also by the lack of secure contact between the monitor and the user. This noisy environment often leads to an irregular, inaccurate or even missing readout of the heart rate.